1. Field of the Invention
The invention relates to a control unit for a vehicle steering system, which controls an electric motor to change a steering angle on the basis of a target route for a vehicle.
2. Discussion of Background
Japanese Patent Application Publication No. 6-336170 (JP 6-336170 A) describes a control unit for a vehicle steering system. The control unit sets a target route on the basis of vehicle front view image monitoring data and changes a steering angle by driving an electric motor on the basis of the target route.
When a steered mechanism operates in accordance with the rotation of a steering shaft, a distortion occurs in components of the steered mechanism. However, the control unit described in JP 6-336170 A controls the electric motor without taking into account a distortion of the steered mechanism. Therefore, there is a possibility that an amount of change in steering angle obtained through the control over the electric motor may deviate from an amount of change in steered angle.